Technical Field
This present application relates to a method of tuning color temperature of light-emitting device, which is especially related to a method of tuning color temperature of light-emitting device having a space between the light-emitting diodes. The space and the overall color temperature of the light-emitting device are positively correlated.
Description of the Related Art
Following incandescent light, a light-emitting diode (LED) has gradually been considered as an alternative light source for the illumination markets to replace the traditional lightings because the LED is less power-consumption, more environmental protection, longevous, light and handy. Among them, those LEDs which can generate white light become the industry's priority for development.
In LED lighting technology, there are two types of white light-emitting diode (WLED). One is formed by using a blue LED chip and a red chip as lighting sources to excite the phosphor by blue chip to emit the yellow light and green light, and then mixing the blue, red, and green or yellow lights to generate the white light. Another is formed by using a blue LED chip as a lighting source to excite phosphor by blue chip to emit the yellow and green light, and then mixing the blue and green or yellow lights to generate the white light. These two kinds of WLEDs are slightly different in price and color temperature, but face the same problem that the color temperature is affected after the package process. Therefore, for better color rendering, output efficiency, and color uniformity, an effective method of tuning color temperature of the LED can expand the utilization of WLEDs.
Moreover, the LED may be further connected to other components in order to form a light-emitting device. The light-emitting device comprises a sub-mount carrying an electrical circuit, a solder formed above the sub-mount to bond the light-emitting device to the sub-mount and to electrically connect the substrate of the light-emitting device with the electric circuit on the sub-mount, and an electrical connection structure that electrically connects the electrode of the light-emitting device to the electric circuit on the sub-mount, wherein the sub-mount may be lead frame or large size mounting substrate in order to facilitate circuit design and heat dissipation.